I have noticed it is much more difficult now to use the mouse to select notes I wish to beam or unbeam. Where it used to be you could use the mouse and click over and pull up the moving box to select them, now it seems it more frequently will select the line above it (if blank, a whole rest) not the notes. It seems to be pretty arbitrary deciding which notes it want me to be able to pull open the square with. Is there a particular keyboard command you can use to beam/unbeam notes- previous version 1.03 worked particularly well when making this move. New version seems to have forgotten its usefulness.
Selection hasn’t changed between Dorico 1.0.30 and Dorico 1.1: you still need to make sure that you completely enclose the noteheads you want to select when you use the marquee selection, just as before. If you’re having problems with marquee selection, I would suggest you use Shift+arrow keys to extend your selection instead and see if you find that any easier.